Reversal of Delirium Induced by Tricyclic Antidepressant Drugs with Physostigmine

The authors found that 2 mg. of physostigmine given intramuscularly was effective in reversing acute brain syndromes in two patients who had ingested toxic doses of drugs with anticholinergic properties (amitriptyline alone and an amitriptyline-perphenazine combination). Physostigmine also controlled one patient's tachycardia and tachypnea. Physostigmine may not control toxic effects of anticholinergic drugs when these effects are not mediated through cholinergic blockade.